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tates This invention relates to an indirect process of printing with vatand sulfur dyestuffs in which a solution of an alkali salt ofstraight-chain or branched hydroxyalkyl sulfinic acid with 2 to 4 carbonatoms is used as reducing agent.

Processes for the printing of textile goods with vat and sulfurdyestulfs are known in which the dyestuff is printed on together withcertain coagulable thickening agents, for example with alkyl celluloseethers, carob bean flour ether, polyvinyl alcohol, ethers of gum guar,alginates or also simple carob bean flour thickening. The printingpastes themselves contain no reducing agent, but now and again alkalineagents, such as potassium or sodium carbonate or also sodium hydroxidedepending on the compatibility of the thickenings with these alkalineagents. After printing and drying, the goods are treated with solutionsof reducing agents, possibly containing alkaline agents, which usuallycontain additions which effect or promote the coagulation of theabove-mentioned thickening agents, such as sodium borate or sodiumaluminate, and in many cases also sodium sulfate. These reducing agentsare sometimes thickened with non-coagulable thickening agents.

Immediately after preparation, for example by means of a foulard orengraved rollers, the textiles, while thus still in a moist state, andsupplied to a heat treatment with exclusion of air. The reduction andfixation of the dyestulfs are thereby achieved. The heat-transferringagent may be air-free saturated or superheated steam of 1 to 3atmospheres absolute, at a temperature of 100 to 200 C. Hot metal bathsor hot oil baths may however also be used, and also hot Water which mayif desired be enriched with agents having an electrolytic action. Theheat may also be transmitted to the moist textile goods by hot metallicsurfaces, the access of atmospheric oxygen to the textile goods beingprevented by a preheated rubber cloth.

In all these methods, which are known under the terms two-phase printingmethods or indirect printing with vat dyestuffs or vat-pigment printingmethods, there is preferably used as reducing agent sodium formaldehydesulfoxylate. and more rarely sodium dithionite. These printing methodsare hereinafter defined as two-phase printing method or two-phaseprinting process.

The advantage of sodium formaldehyde sulfoxylate solutions lies in thestability of these solutions at 20 C. and also in the fact that thesesolutions still do not have a reducing action on vat dyestuffs at 20 C.Thus when padding the printed fabric web in the foulard chassis theredoes not occur either a vatting of the printed dyestuft (andconsequently a bleeding out onto the unprinted places) or a staining ortinting of the padding liquor. When it is desired to achieve with thedevelopment of the printed dyestuif a simultaneous coloring of theunprinted places in pale shades, there may be added to the sodiumformaldehyde sulfoxylate solution a small amount of a vat and/ or sulfurdyestulf.

It is however disadvantageous that when using sodium formaldehydesulfoxylate as reducing agent in the usual steamers, treatment times of3 to 5 minutes per square meter weight of the textile web are requiredin atent order completely to fix the dyestufi printed on. If sodiumdithionite is used as reducing agent, it is true that shorter steamingtimes of about 30 seconds duration are possible, but it is adisadvantage that sodium dithionite solutions reduce vat dyestuffsalready at 20 C. in the presence of alkali hydroxides and/or alkalicarbonates. This gives rise to the following consequences; the printedvat dyestuffs vat in the preparation in the foulard chassis, bleed intothe nonprinted ground and also tint or stain the padding liquor or thethickened sodium dithionite solution in an undesirable way.

The instability of cold sodium dithionite solutions, also in thepresence of alkaline agents, is also disadvantageous. Thus when usingsodium dithionite fixation it is necessary to prepare the padding liquorfor the treatment of the fabric fresh at short intervals, i.e. atintervals of 30 to minutes.

With this state of the art, methods were sought after which wouldcombine the advantages of reduction with sodium dithionite and theadvantages of reduction with sodium formaldehyde sulfoxylate withoutexhibiting the disadvantages which the use of these reducing agentsoccasions.

We have found that textile goods can be printed with dyestuffs selectedfrom the group consisting of vat dyestuffs and sulfur dyestufis by:

(1) Printing the goods in the first stage with dyestuffs with theaddition of coagulable thickening agents and, after drying, fixing theprints in a second stage by treatment with a solution of an alkali saltof a straightchain or branched hydroxy-alkyl sulfinic acid with 2 to 4carbon atoms which contains an alkaline agent and subsequent short heattreatment,

(2) Printing the goods in the first stage with dyestuffs with theaddition of alkaline agents and coagulable thickening agents and, afterdrying, fixing the prints in a second stage by treatment with a solutionof an alkali salt of a straight-chain or branched hydroxy-alkyl sulfinicacid with 2 to 4 carbon atoms and subsequent short heat treatment,

(3) Printing the goods in the first stage with dyestuff-s with theaddition of non-co-agulable thickening agents and, after drying, fixingthe prints in a second stage by spraying on a solution, containing analkaline agent, of an alkali salt of a hydroxy-alkyl sulfinic acid with2 to 4 carbon atoms and subsequent short heat treatment, or

(4) Printing the goods in the first stage with dyestuffs with theaddition of alkaline agents and non-coagulable thickening agents andfixing the prints in a second stage by spraying on a solution of analkali salt of a hydroxy-alkyl sulfinic acid with 2 to 4 carbon atomsand subsequent short heat treatment.

Included in the term textile goods are to be understood structures, suchas woven or knitted fabrics, especially those of native and/orregenerated cellulose, natural silk or linear polyamides. As alkalisalts of hydroxy-alkyl sulfinic acids with 2 to 4 carbon atoms there maybe mentioned for example the sodium, potassium or ammonium salts ofhydroxy-ethane sulfinic acid, hydroxy-normal-propane sulfinic acid,hydroxy-iso-propane sulfinic acid or hydroxy-normal-butane sulfinicacid,and as alkaline agents there may be mentioned for example sodiumhydroxide, potassium hydroxide, sodium carbonate or potassium carbonateand/or mixtures of the same. As coagulable thickening agents there maybe mentioned for example alkyl cellulose ethers, carob bean flour ether,polyvinyl alcohol, ethers of gum guar, alginates or also simple carobbean flour thickenings and, as non-coagulable thickening agents theremay be mentioned for example tragacanth mucilage. The fixation of theprints is effected by a short heat treatment of 10 to 60 secondsduration at a temperature of 80 to 200 C., advantageously between 90 and120 C.

The preparation of the sulfinic acid compounds employed in the processof the invention can be accomplished by well known methods, e.g. byreaction of the corresponding aldehydes or ketones with metalhyposulfites, preferably sodium or zinc hyposulfites. The resultingproducts are the metal salts of hydroxy-alkyl sulfinic acids with 2 to 4carbon atoms. See, for example, the preparation of sulfinic acids asdisclosed by Gilman, Organic Chemistry, vol. I, pp. 9l3-9l9, 2nd ed.,John Wiley & Sons, Inc., New York (1949).

Solutions of alkali salts of hydroxy-alkyl sulfinic acids with '2 to 4carbon atoms can be obtained for example by dissolving the correspondingsalts in water. Such solutions may however also be obtained from thesalts of hydroxy-alkyl sulfinic acids with 2 to 4 carbon atoms which aredifiicultly soluble in water, for example the calcium, barium, di-zincor mono-zinc salts, by treatment with aqueous solutions of alkalihydroxides or carbonates, for example sodium or potassium hydroxide orcarbonate, by so-called double decomposition.

An advantage of the new process consists in the fact that the alkalisalts of straight-chain or branched hydroxy-alkyl sulfinic acids with 2to 4 carbon atoms used as reducing agents, and which do not reducedyestuffs at room temperature even in the presence of strongly alkalineagents, such as sodium or potassium hydroxide, and therefore do notcause any detachment of dyestuff in the padding liquor during thepreparation of the printed fabric, have such a high decomposition speedat temperatures above 50 C. that the dyestuffs can be fixed on the fiberwith a heat treatment which is just as short as when using sodiumdithionite as reducing agent. The new rapid fixing process moreoverpermits the use of a far greater number of vat dyestuffs than hitherto,because when using sodium dithionite only those vat dyestuffs could beused which by reason of their high leuco dyestuif potential were notreduced by cold hyposulfite solutions. The stability of aqueoussolutions of the alkali salts of straight-chain or branchedhydroxy-alkyl sulfinic acids with 2 to 4 carbon atoms is so great evenat 20 C. against the oxygen and carbon dioxide content of the air thataqueous solutions can be sprayed onto the printed textile goods withoutsuffering appreciable loss of reducing agent. On the contrary if aqueoussodium dithionite solutions are sprayed, usually only between and 30% ofthe reducing agent originally present can be detected in the solutioncollected after spraying. It is true that aqueous solutions of sodiumformaldehyde sulfoxylate can be sprayed without appreciable diminutionin reducing value but it is known that the use of this reducing agentnecessitates a much longer heat treatment of the textile goods for thefixation of the dyestuffs. On the contrary if the printed fabric issprayed, as above described, with aqueous solutions of alkali salts ofstraightchain or branched hydroxy-alkyl sufinic acids with 2 to 4 carbonatoms it is possible on the one hand to use short heat treatment periodsand on the other hand it is no longer essential to use coagulablethickenings in the printing pastes.

The following examples will further illustrate this invention but theinvention is not restricted to these examples. The parts and percentagesspecified are parts and percentages by weight.

Example 1 A cotton fabric is printed with the following printing paste:

100 parts of a yellow vat dyestuif, for example Vat Yellow 1, 0.1. 70600(Color Index, 1956, volume 2, page 2427) in the form of a 20% aqueouspaste;

100 parts of water;

600 parts of a 3% decoction of carob bean flour; and

- 4 200 parts of a 10% wheat starch paste (making 1000 parts in all).

After printing and drying, the fabric is prepared with:

800 parts of water;

200 parts of a 30% aqueous solution of the potassium salt, ofhydroxy-ethane sulfinic acid;

50 parts of sodium hydroxide; and

5 parts of sodium tetraborate.

The fabric, while still moist, is then exposed for 30 seconds to anair-free steam atmosphere without excess pressure at 108 C. To finishoff" the print, the fabric is treated for 2 minutes in flowing water at20 C., oxidized for 2 minutes in an aqueous solution at C. whichcontains 2 grams of sodium perborate per liter, soaped, rinsed anddried. A brilliant yellow print on a white ground is obtained.

The same result is achieved when the prepared still moist fabric,instead of being subjected to the 30 seconds steaming process, isapplied to a metallic surface heated to'l10 C. and covered with a rubbercloth preheated to about 80 'C., the said heat treatment lasting for 25seconds.

Example 2 A viscose rayon staple fiber fabric is printed with thefollowing printing paste:

parts of a blue vat dyestuif, for example Vat Blue 14, CI. 69810 (ColorIndex, 1956, volume 2, page 2501) in the form of a 15% aqueous paste;

50 parts of water;

600 parts of a 4.5% carob bean flour decoction in water;

200 parts of a 10% maize starch paste;

30 parts of potassium carbonate; and

20 parts of sodium hydroxide (making 1000 parts in all).

After printing and drying, it is treated with a solution of:

850 parts of water;

150 parts of a 40% aqueous solution of the potassium salt ofhydroxypropane sulfinic acid; and

15 parts of sodium tetraborate.

Example 3 A cotton fabric is printed with the following printing paste:

100 parts of a yellow vat dyestuff, for example Vat Yellow 1, CI. 70600(Color Index, 1956, volume 2, page 2427) in the form of a 20% aqueouspaste;

150 parts of water;

500 parts of 6% tragacanth mucilage; and

250 parts of a 10% wheat starch paste (making 1000 parts in all).

The printed and dried fabric is sprayed with the following solution sothat the fabric absorbs at least 50% of its own weight of solution:

800 parts of Water;

200 parts of a 40% aqueous solution of the sodium salt of hydroxy-ethanesulfinic acid; and

50 parts of sodium hydroxide.

The still moist fabric is continuously supplied to a steamer and theretreated for 30 seconds at about C. in air-free steam without excesspressure. The fabric is finished off according to Example 1.

A brilliant yellow print is obtained on a white ground.

Instead of the solution of the sodium salt of hydroxyethane sulfinicacid, there may also be used a solution of the ammonium salt ofhydroxy-ethane sulfinic acid under otherwise identical conditions.

Example 4 A cuprammonium rayon fabric is printed with the followingpaste:

800 parts of water;

200 parts of a 35% aqueous solution of the sodium salt of hydroxy-butanesulfinic acid; and

50 parts of sodium hydroxide.

The still moist fabric is continuously supplied to a steamer and treatedtherein for 30 seconds at 110 C. with air-free steam. The finishing offof the fabric takes place in the same way as described in Example 1.

The result is a brilliant red-violet print on a white ground.

Instead of the sodium salt of hydroxy-butane sulfinic acid there mayalso be used the sodium, potassium or ammonium salts ofhydroxy-iso-propane sulfinic acid or their aqueous solutions.

Example 5 A natural silk fabric is printed according to the followingprescription:

40 parts of a green vat dyestufi, for example Vat Green 1, CI. 59855(Color Index, 1956, volume 2, page 2519) in the form of a aqueous paste;

210 parts of water;

500 parts of a 5% alkyl cellulose ether thickening; and

250 par-ts of a 10% wheat starch thickening (making 1000 parts in all).

After printing and drying, it is padded on the foulard with thefollowing solution:

850 parts of water;

150 parts of a 30% aqueous solution of the sodium salt of hydroxy-ethanesulfinic acid;

parts of sodium hydroxide; and

25 parts of potassium carbonate.

The still moist material is treated for 60 seconds at 0.3 atmosphereexcess pressure with air free steam. The further finishing oif takesplace according to Example 1.

The product is a brilliant green print on a white ground.

The alkyl cellulose ether thickening may also be replaced by the sameamount of a 17% polyvinyl alcohol thickening.

Example 6 A fabric of polycaprolactam fibrous material is printed withthe following paste:

40 parts of a green vat dyestuff, for example Vat Green 1, CI. 59855(Color Index, 195 6, volume 2, page 2519) in the form of a 10% aqueouspaste;

110 parts of water;

600 parts of a 5% sodium alginate thickening; and

250 parts of a 10% wheat starch paste.

After printing and drying, it is padded with the following solution on atwo-roller foulard:

800 parts of water;

15 parts of aluminum sulfate (anhydrous);

45 parts of sodium hydroxide;

40 parts of sodium carbonate (calcined); and

200 parts of a 40% aqueous solution of the potassium salt ofhydroxy-ethane sulfinic acid.

The moist fabric is supplied continuously to a steamer and treatedtherein for 50 seconds with air-free steam at 105 C. The steamed printis finished off according to Example 1 and a full bluish-green print isobtained on a white ground.

Steaming may also be for 40 seconds at an excess pressure of 1.5atmospheres.

Example 7 A cotton fabric is printed with the following printing paste:

20 parts of a grey vat dyestuif, for example Vat Black 25, Cl. 69525(Color Index, 1956, volume 2, page 2560) in the form of a 20% aqueouspaste;

130 parts of water;

600 parts of a 4.5% gum guar ether decoction in water;

and

250 parts of a 10% wheat starch paste (making 1000 parts in all).

After printing and drying it is padded on the tworoller foulard with thefollowing solution:

850 parts of water;

150 parts of a 30% aqueous solution of the potassium salt ofhydroxy-ethane sulfinic acid;

20 parts of sodium tetraborate; and

50 parts of sodium hydroxide.

The still m'oist fabric is led through the following solution heated toC. for the heat treatment:

730 parts of Water;

200 parts of anhydrous sodium sulfate; 20 parts of sodium tetraborate;and

20 parts of sodium hydroxide.

The period of treatment in this solution lasts for 40 seconds. Thefinishing lofi, such as oxidation, soaping and rinsing, of the printtakes place as in Example 1.

Gray prints on a white ground are obtained.

Example 8 A cotton fabric is printed with the following paste:

70 parts of a yellow vat dyestufi, for example Vat Yellow .2, C.-I.67300 (Color Index, 1956, volume 2, page 2428) in the form of a 20%aqueous paste; 30 parts of water; 600 parts of a 4.5% carob bean flourether thickening;

and 300 parts of a 10% wheat starch paste (making 1000 parts in all).

After printing and drying, the following thickened solution of reducingagent is printed on by means of a roller engraved over the wholesurface:

700 parts of water;

parts of a 6% tragacanth mucilage;

200 parts of a 40% solution of the sodium salt of hydroxy-ethanesulfinic acid; and

60 parts of sodium hydroxide.

The fabric is then treated for 35 seconds in air-free steam at C.without the use of excess pressure. The finishing off of the print takesplace according to Example 1.

A brilliant greenish-yellow print is obtained on a white ground.

1 to 3% of sodium tetraborate may also be added to '7 the thickenedsolution of reducing agent for the coagulation of the carob bean flourether thickening.

Example 9 The printed and dried fabric is prepared with the followingsolution of reducing agent on the two-roller foulard:

750 parts of water; parts of a yellow vat dyestuff, for example VatYellow 1, Cl. 70600 (Color Index, 1956, volume 2, page 2427) in the formof a 20% aqueous paste;

200 parts of a 40% solution of the sodium salt of hydroxy-ethanesulfinic acid;

50 parts of sodium hydroxide; and

15 parts of sodium tetraborate.

The fabric is then treated for 30 seconds in air-free steam at 110 C.without excess pressure. The finishing off of the steamed fabric iscarried out as in Example 1.

A red print on a yellow ground is obtained.

The solution of reducing agent containing vat dyestuff may also bethickened with 100 parts of a 6% tragacanth mucilage while omitting thesame amount of water, and this thickened solution applied by means of aroller engraved over its whole surface.

Example 10 A white cotton fabric is printed according to the followingprescription:

50 parts of a yellow sulfur dyestulf, for example C.l. Sulfur Yellow 5(Color Index, 1956, volume 2, page 2365);

parts of crystallized sodium sulfide;

135 parts of water;

600 parts of 6% tragacanth mucilage; and

200 parts \of 10% wheat starch paste (making 1000 parts in all).

After printing and drying, the fabric is sprayed with a solution of 900parts of water;

100 parts of a 40% aqueous solution of the sodium salt of hydroxy-ethanesulfinic acid; and

50 parts of sodium hydroxide.

The still moist fabric is supplied continuously to a steamer and treatedtherein for 45 seconds in air-free steam at 110 C. The finishing off ofthe print, such as oxidation, soaping and rinsing, takes place as inExample 1.

A yellow print is obtained on a white ground.

Instead of the said yellow sulfur dyestuif there may also be used abrown sulfur dyestuff, for example C.I. Sulfur Brown 16, CI. 53285(Color Index, 1956, volume 2).

In this case a deep brown print is obtained on a white ground.

Example 11 A white cotton fabric is printed with the printing pastedescribed in Example 8 and dried. Then 50 parts of sodium hydroxide;

15 parts of sodium tetraborate; and

100 parts of the di-zinc salt of hydroxy-ethane sulfinic acid are addedto 1000 parts of water. The mixture is stirred occasionally during thecourse of 10 minutes and then allowed to stand for 30 minutes. Duringthis time the readily soluble sodium salt of hydroxy-ethane sulfinicacid forms from the diflicultly soluble di-zinc salt. The solution iscarefully decanted from the sediment. With the solution of the sodiumsalt of hydroxy-ethane sulfinic acid containing sodium hydroxide andsodium tetraborate thus obtained, the fabric is prepared on thetworoller foulard and subsequently steamed for 20 seconds in air-freesteam at 105 C. The finishing olf, consisting of oxidation, soaping andrinsing, takes place as described in Example 1. A yellow print isobtained on a white ground. The same result is obtained when, instead ofbeing subjected to the steaming process lasting 20 seconds, the preparedfabric is led over a drum heated with steam with the fabric lyingclosely against the surface of the drum and protected from the action ofatmospheric oxygen by being covered with a heat-stable elastic rubber orplastic cover, this heat treatment being allowed to last for 20 seconds.

Example 12 A white cotton fabric is printed with the following printingpaste and dried:

30 parts of a violet vat dyestuff, for example Vat Violet 1, CI. 60010(Color Index, 1956, volume 2, page 2479) in the form of a 15% aqueouspaste;

120 parts of water;

600 parts of a 4.5% carob bean flour ether decoction in water;

200 parts of a 10% wheat starch paste; and

50 parts of sodium hydroxide (making 1000 parts in all).

Then

20 parts of sodium hydroxide;

87 parts of the di-Zinc salt of hydroxy-ethane sulfinic acid; and

15 parts of sodium tetraborate are added to 1000 parts of water. It isstirred occasionally during the course of 10 minutes and the mixturethen allowed to stand for 30 minutes. After this period, the solution ofthe sodium salt of hydroxy-ethane sulfinic acid containing sodiumhydroxide and sodium tetraborate is carefully decanted from the sedimentand the fabric is prepared therewith. Then it is treated for 30 secondsin air-free steam at 105 C. The finshing off, consisting of oxidation,soaping and rinsing, takes place as described in Example 1. A violetprint is obtained on a white ground.

The di-zinc salt of hydroxy-ethane sulfinic acid may also be replaced byparts of the more readily soluble mono-zinc salt of hydroxy-ethanesulfinic acid if 27 parts of sodium hydroxide are used instead of 20parts.

Example 13 A white cotton fabric is printed with the following printingpaste and dried:

30 parts of a violet vat dyestuif, for example Vat Violet 1, 0.1. 60010(Color Index, 1956, volume 2, page 2479) in the form of a 15 aqueouspaste;

50 parts of Water;

700 parts of a 4.5% carob bean flour ether decoction in water; and

220 parts of a 10% wheat starch paste (making 1000 parts in all).

Then the following are introduced into 900 parts of water at intervalsof 10 minutes between each addition:

parts of potassium carbonate;

100 parts of the calcium salt of hydroxy-ethane sulfinic acid 30 partsof sodium hydroxide and 15 parts of sodium tetraborate,

with light stirring and the mixture is allowed to stand for 1 hour. Inthe course of this time, the potassium salt of hydroxy-ethane sulfinicacid, which is readily soluble in water, forms from the calcium saltwhich is diflicultly soluble in water, and calcium carbonate remains asa precipitate difiicultly soluble in water at the bottom of the vessel.The supernatant solution is decanted from the sediment and the fabric isprepared with the resultant solution of the potassium salt ofhydroxyethane sulfinic acid containing sodium hydroxide and sodiumtetrab orate with the aid of a two-roller foulard and then steamed for30 seconds in air-free steam at 110 C. The finishing 01f, consisting ofoxidation, soaping and rinsing, takes place according to Example 1. Aviolet print is obtained on a white ground.

For the production of the above described preparation solution there maybe used, instead of the calcium salt, also the corresponding amount ofthe barium salt of hydroxy-ethane sulfinic acid. The same result isobtained under otherwise unchanged working conditions.

We claim:

1. In a two-phase printing process for printing textile materials with adyestuff selected from the class consisting of vat dyestuffs and sulfurdyestuffs wherein said textile material is treated in a first stage byprinting thereon a composition containing said dyestuff and a thickeningagent and then drying said textile material and in a second stage byapplying a reducing agent to said textile material and then heating fora short period of time sufficient to fix said dyestuif on said textilematerial, an alkaline agent also being applied to said textile materialin at least one f said two stages, the improvement which comprises:using as the reducing agent in said second stage an alkali salt of ahydroxyalkyl sulfinic acid with from 2 to 4 carbon atoms, and heatingsaid textile material in said second stage for a period of time of about10 to 60 seconds at a temperature between 80 C. and 200 C. whereby saiddyestufl is fixed on said textile material.

2. An improved pnocess as claimed in claim 1 wherein the heatingtemperature is between about 90 C. and 120 C.

3. In a two-phase printing process for printing textile materials with adyestufi selected from the class consisting of vat dyestulfs and sulfurdyestufis wherein said textile material is printed in a first stage witha composition containing said dyestufi and a coagulable thickening agentand then dried, and the print is fixed in a second stage by applying asolution, containing an alkaline agent, of a reducing agent and thenheating for a period of time of about 10 to 60 seconds at a temperaturebetween about 80 C. and 200 C., the improvement which comprises:employing as the reducing agent in said second stage an alkali salt of ahydroxyalkyl sulfinic acid with from 2 to 4 carbon atoms.

4. In a two-phase printing process for printing textile materials With adyestufi selected from the class consisting of vat dyestufis and sulfurdyestuifs wherein said textile material is printed in a first stage witha composition containing said dyestuff, an alkaline agent and acoagulable thickening agent and then dried, and the print is fixed in asecond stage by applying a solution of a reducing agent and then heatingfor a period of time of about 10 to seconds at a temperature betweenabout C. and 200 C., the improvement which oomprises: employing as thereducing agent in said second stage an alkali salt of a hydroxyalkylsulfinic acid with from 2 to 4 carbon atoms.

5. In a two-phase printing process for printing textile materials with adyestuff selected from the class consisting of vat dyestuffs and sulfurdyestuffs wherein said textile material is printed in a first stage witha composition containing said dyestuff and a non-coagulable thickeningagent and then dried, and the print is fixed in a second stage byapplying a solution, containing an alkaline agent, of a reducing agentand then heating for a period of time of about 10 to 60 seconds at atemperature between 80 C. and 200 C., the improvement which comprises:employing as the reducing agent in said second stage an alkali salt of ahydroxyalkyl sulfinic acid with from 2 to 4 carbon atoms.

6. In a two-phase printing process for printing textile materials with adyestuif selected from the class consisting of vat dyestuffs and sulfurdyestufis wherein said textile material is printed in a first stage witha. composition containing said dyestufi, an alkaline agent and anon-coagulable thickening agent and then dried, and the print is fixedin a second stage by applying a solution of a reducing agent and thenheating for a period of time of about 10 to 60 seconds at a temperaturebetween about 80 C. and 200 C., the improvement which comprises:employing as the reducing agent in said second stage an alkali salt of ahydroxyalkyl sulfinic acid with from 2 to 4 carbon atoms.

7. A improved process as claimed in claim 1 wherein the reducing agentis the sodium salt of hydroxy-ethane sulfinic acid.

8. An improved process as claimed in claim 1 wherein the reducing agentis the potassium salt of hydroxyethane sulfinic acid.

References Cited in the file of this patent UNITED STATES PATENTS2,164,930 Lubs July 4, 1939 2,276,704 Schneevoigt. Mar. 17, 19422,315,514 Fox Apr. 6, 194-3 2,412,909 Potter Dec. 17, 1946

1. IN A TWO-PHASE PRINTING PROCESS FOR PRINTING TEXTILE MATERIALS WITH A DYESTUFF SELECTED FROM THE CLASS CONSISTING OF VAT DYESTUFFS AND SULFUR DYESTUFFS WHEREIN SAID TEXTILE MATERIAL IS TREATED IN A FIRST STAGE BY PRINTING THEREON A COMPOSITION CONTAINING SAID DYESTUFF AND A THICKENING AGENT AND THEN DRYING SAID TEXTILE MATERIAL AND IN A SECOND STAGE BY APPLYING A REDUCING AGENT TO SAID TEXTILE MATERIAL AND THEN HEATING FOR A SHORT PERIOD OF TIME SUFFICIENT TO FIX SAID DYESTUFF ON SAID TEXTILE MATERIAL, AN ALKALINE AGENT ALSO BEING APPLIED TO SAID TEXTILE MATERIAL IN AT LEAST ONE OF SAID TWO STAGES, THE IMPROVEMENT WHICH COMPRISES: USING AS THE REDUCING AGENT IN SAID SECOND STAGE AN ALKALI SALT OF A HYDROXYALKYL SULFINIC ACID WITH FROM 2 TO 4 CARBON ATOMS, AND HEATING SAID TEXTILE MATERIAL IN SAID SECOND STAGE FOR A PERIOD OF TIME OF ABOUT 10 TO 60 SECONDS AT A TEMPERATURE BETWEEN 80* C. AND 200*C. WHEREBY SAID DYESTUFF IS FIXED ON SAID TEXTILE MATERIAL. 